The present embodiments relate to real-time marker detection in medical imaging.
Coronary heart disease, which is a narrowing of the coronary arteries, is the leading cause of death for both men and women. To treat coronary heart disease, an intervention, such as a Percutaneous Coronary Intervention (PCI) procedure, may be used. During the PCI procedure, a balloon-equipped stent is inserted into the coronary artery. A guide wire body inside the balloon is anchored by markers that provide visual indication of the position of the balloon and the stent. Once the stent reaches the desired position, the balloon expands the stent, which is, in turn, permanently left in the coronary artery.
Proper visualization of the stent, including the location of the stent, the surrounding tissue, and geometry of the stent is important to ensure the quality of the stent deployment and stent expansion. Stent under-expansion may lead to stent thrombosis and restenosis. Stent deployment is typically monitored by X-ray fluoroscopy, in which the visibility of the guide wire, markers, and the stent is often quite low. Due to poor visibility, poor contrast, nearby similar structures, and the rapid motion of the markers (due to, for example, cardiac and breathing motion), physicians often have a difficult time precisely deploying and/or expanding the stent using real-time fluoroscopic images. Accordingly, the stent may not be implanted precisely at the desired location and/or the stent may not be properly expanded against the artery wall.
Various image processing techniques have been proposed to improve the quality of fluoroscopy images and, in turn, provide better stent visibility. One example is motion-compensated noise reduction applied via a landmark-based registration of multiple images. Another example is a low-level image processing technique known as blob detection. Such image processing techniques may, however, produce many false positives, are conducted offline such that the physician can only observe the stent in one static image, result in information being lost and/or distorted, or require significant user intervention (e.g., for initialization, correction, and/or selection).